Glossary 321
Dormer A structure that projects from a sloping roof to form another roofed area. This new area is
typically used to provide a surface to install a window.
Downspouts Pipes connected to the gutter to conduct rainwater to the ground or sewer.
Drawing Number An identifying number assigned to a drawing or a series of drawings.
Drawings The collection of lines illustrating the shape and features of a part. The original graphic de-
sign from which a blueprint may be made; also called plans.
Drywall An interior wall covering installed in large sheets made from gypsum board.
Duct Usually sheet metal forms used for the distribution of cool or warm air throughout a structure.
Due Diligence The process of conducting a walkthrough survey and appropriate inquiries into the
physical condition of a commercial real estate’s improvements, usually in connection with a commercial
real estate transaction. The degree and type of such survey or other inquiry may vary for different proper-
ties and different purposes.
Dwelling Unit A single unit which provides a kitchen or food preparation area, in addition to rooms
and spaces for living, bathing, sleeping, and the like. Dwelling units include a single family home or a town-
house used as a transient group home; an apartment building used as a shelter; guestrooms in a hotel that
provide sleeping accommodations and food preparation areas; and other similar facilities used on a tran-
sient basis. For purposes of these guidelines, use of the term “Dwelling Unit” does not imply the unit is used
as a residence.
Easement The right or privilege to have access to or through another piece of property such as a
utility easement.
Eave That portion of the roof that extends beyond the outside wall.
Egress A continuous and unobstructed way of exit travel from any point in a building or facility to a
public way. A means of egress comprises vertical and horizontal travel and may include intervening room
spaces, doorways, hallways, corridors, passageways, balconies, ramps, stairs, enclosures, lobbies, hori-
zontal exits, courts and yards. An accessible means of egress is one that complies with these guidelines
and does not include stairs, steps, or escalators. Areas of rescue assistance or evacuation elevators may
be included as part of accessible means of egress.
Elastomeric A material having characteristics which allow it to expand or contract its shape and still
return to its original dimensions without losing stability.
Electromechanical Drawing A special type of drawing combining electrical symbols and mechani-
cal drawing to show the position of equipment that combines electrical and mechanical features.
Element An architectural or mechanical component of a building, facility, space, or site, e.g., tele-
phone, curb ramp, door, drinking fountain, seating, or water closet.
Elementary Wiring Diagram (1) A shipboard wiring diagram showing how each individual conduc-
tor is connected within the various connection boxes of an electrical circuit system. (2) A schematic dia-
gram; the term elementary wiring diagram is sometimes used interchangeably with schematic diagram, es-
pecially a simplified schematic diagram.
Elevations A four-view drawing of a structure showing front, sides, and rear.
Engineer’s Scale The scale used whenever dimensions are in feet and decimal parts of a foot, or
when the scale ratio is a multiple of 10.
Epicenter The point of the earth’s surface directly above the focus or hypocenter of an earthquake.
Expansion Joint A joint often installed in concrete construction to reduce cracking and to provide
workable areas.